Diabetes is a disease in which the body does not produce or properly use insulin. Millions of people in the United States and around the world have been diagnosed with some form of diabetes. Type 1 diabetes results from the body's failure to produce insulin. Type 2 diabetes results from insulin resistance in which the body fails to properly use insulin. In order to effectively manage the disease, diabetics must closely monitor and manage their blood glucose levels through exercise, diet and medications. In particular, both Type 1 and Type 2 diabetics rely on insulin delivery and blood glucose monitoring to control their diabetes.
External infusion devices have been used to deliver medication to a patient as generally described in U.S. Pat. Nos. 6,554,798 and 6,551,276 which are specifically incorporated by reference herein. In addition to delivering medication to a patient, other medical devices have been used to determine body characteristics by obtaining a sample of bodily fluid. A variety of implantable electrochemical sensors have been developed for detecting and/or quantifying specific agents or compositions in a patient's blood. For instance, glucose sensors have been developed for use in obtaining an indication of blood glucose levels in a diabetic patient. Such readings can be especially useful in monitoring and/or adjusting a treatment regimen that typically includes the regular administration of insulin to the patient. Thus, blood glucose readings are particularly useful in improving medical therapies with semi-automated medication infusion pumps of the external type and/or implantable type.
Monitoring blood glucose levels plays an integral role in the management and control of diabetes. Finger stick measurements, glucose sensors and monitors have traditionally been used to check the blood glucose levels of diabetic patients. In recent years, continuous glucose monitoring systems have been developed utilizing the latest sensor technologies incorporating both implantable and external sensors as generally described in U.S. Pat. No. 5,391,250 entitled “Method of Fabricating Thin Film Sensors”, U.S. Pat. No. 6,484,046 entitled “Electrochemical Analyte Sensor,” and U.S. Pat. Nos. 5,390,671, 5,568,806 and 5,586,553, entitled “Transcutaneous Sensor Insertion Set,” all of which are specifically incorporated by reference herein. Newer systems deliver the preciseness of finger stick measurements coupled with the convenience of not having to repeatedly prick the skin to obtain glucose measurements. These newer systems provide the equivalent of over 200 finger stick readings per day. Additionally, continuous glucose monitoring systems allow physicians and patients to monitor blood glucose trends of their body and suggest and deliver insulin based on each patient's particular needs. Accordingly, physicians and medical device companies are always searching for more convenient ways to keep diabetic patients aware of their blood glucose levels throughout the day.
As such, physiological characteristic (or analyte) sensors may be generally used to test analyte levels in patients. For example, thin film sensors may be used for obtaining an indication of blood glucose levels and monitoring blood glucose levels in a diabetic patient. In these instances, a portion of a glucose sensor is positioned subcutaneously/transcutaneously in direct contact with patient extracellular fluid. Glucose sensor readings can be especially useful in adjusting a treatment regimen that typically includes regular administration of insulin to the patient.
A glucose sensor may be packaged and sold as a product that includes certain features or components that allow the patient to position and subcutaneously/transcutaneously implant the sensor. For example, thin film glucose sensors are often implanted subcutaneously/transcutaneously using an introducer needle, which is packaged with the glucose sensor. The introducer needle is used to puncture the skin of a patient at the same time as the sensor is introduced. The introducer needle is then withdrawn, leaving the sensor in the skin of the patient. The introducer needle is used and then discarded after inserting the sensor at the sensor site. Currently, some sensor platforms use a multiple-use, durable insertion device. This type of durable insertion device presents various issues. For example, the use model for this type of durable insertion device is generally complex, that is, the current process requires many complex steps, some of which may require fine motor skills for the user. Current durable insertion devices are also prone to wear and damage. Also, in general, current sensor platforms require users to carry both packaged sensors and an insertion device. If the user is not carrying the insertion device, the user cannot insert the sensor. In addition, durable insertion devices generally require disinfection or cleaning such as in a clinical setting.
Once a continuous glucose sensor is inserted, the continuous glucose sensor is designed to monitor glucose concentration of the patient and a sensor signal is produced that is representative of the glucose concentration. The continuous glucose sensor may use wireless data communication techniques to transmit data indicative of the blood glucose levels to a receiving device such as a portable infusion pump, a glucose monitor device, and/or the like. For example, the transmitted sensor signal may be used to generate a controller input for a controller to generate commands that affect the operation of a delivery system to infuse a liquid, which includes insulin, into the patient.
Typical devices or products generally include a sensor and a transmitter that are placed side by side.